Conventional systems for viewing a stereoscopic image without use of 3D specialty glasses include a parallax barrier system and a lenticular system. In the parallax barrier system, images from a plurality of different viewpoints are displayed on an image display unit such as a PDP. For example, in the case of two viewpoints, a left-view image and a right-view image are displayed. Stereoscopic viewing is enabled by using a parallax barrier to separate the plurality of images in a manner such that a left eye of a viewer views the left-view image and a right eye of the viewer views the right-view image. The parallax barrier is a masking plate including masking portions which mask light and aperture portions which transmit light. The parallax barrier has a function of separating the plurality of images by using the masking portions to control direction of light emitted from the image display unit.
The parallax barrier is designed under a premise that the viewer is viewing from a position which is suitable for stereoscopic viewing (referred to below as an optimum viewing position). When the viewer is not viewing from the optimum viewing position a state may occur in which the left eye views the right-view image in addition to the left-view image and in which the right eye views the left-view image in addition to the right-view image. The aforementioned state is referred to as “cross-talk”.
In order to reduce cross-talk, a system has been proposed in which position of a viewer is detected, and subsequently display position of a left-view image and display position of a right-view image on an image display unit is controlled in accordance with the position of the viewer (for example, Patent Literature 1).